The short-term and long-term regulation of cyclic nucleotide levels and of their metabolic enzymes, adenylate and guanylate cyclases and phosphodiesterases, by hormones and drugs will be studied in glioma (rat C-6) and neuroblastoma (mouse C-1300) cell lines. Regulation of energy metabolism, glycolysis, and the pentose phosphate shunt, particularly as affected by either thiamine deficiency or local anesthetics, will also be examined.